The [link=http://www.nitroplanes.com/edfpruc10eld1.html]EDF Predator UCAV[/link] from Nitro Planes is a large fiberglass jet model with sheeted wings. It comes complete with landing gear, fiberglass canopy, missiles, and all hardware. The model can be powered by a 90mm to 101mm ( 3.5" to 4" ) EDF unit.

The fuselage and parts come well secured in the custom box. All the parts are covered in plastic or bagged. The control surfaces arrive attached with hinge material but need to be CA'ed in place after alignment.

The fiberglass canopy is pre-finished and only needs the latch mechanism attached. The landing gear are fixed with a steerable nose wheel assembly. Two sheets of finishing decals are supplied and the 7-page manual, although sparse, provides sufficient photos and text to complete the model by an experienced assembler.

A closer look at the fuselage reveals the size, quality finish, construction techniques, and high level of pre-assembly. The T-nuts are already installed, and glued in place, for the gear mains and steerable nose wheel assembly. The battery and servo trays are also pre-installed.

Yes, the aluminum wing tube appears to be fine at first glance and touch. We'll know more as I assemble the ARF.

My power system will be a WeMoTec Midi Pro 90mm EDF, AMMO 36-88-1280kV Inrunner Brushless motor, Castle Creations HV85 ESC, and an 8s FlightPower LiPo pack. The motor appears to be a great fit for high-powering a low-cost 90mm EDF and at only $100. On an 8s LiPo supply, it can provide burst power up to 2000 watts at a 74amp burst current. This delivers 6.9lbs of EDF thrust and is within the AMMO 36-88-1280kV Inrunner [link=http://www.electrifly.com/motors/motors-ammo-36-88.html]specifications[/link].[ul][*] WeMoTec [link=http://www.hobby-lobby.com/ductfan.htm]WMD0015[/link] Midi Fan PRO for 5mm Shaft Motors [*] Great Planes ElectriFly Ammo [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXLXA1&P=7]36-88-1280kV[/link] Brushless Electric Motor[*] Castle Creations Phoenix [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXLBY4&P=ML]HV85[/link] ESC[*] Two FlightPower [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXRWA2&P=7]EVO25[/link] 3700mAh 4-cell (14.8v) LiPo batteries in series
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After gluing in a pair of 2-1/4" long hardwood slats, the Midi Pro fan fit perfectly in the ducted fan bay. I'll be using the air intake ring that comes with the Midi Pro fan because the bay area opens into a large area.

My current plan is to start with the stock fixed gear and do grass take-offs. This is largely due to the constraints of reviewing the model unmodified. If the model flies well and goes as fast as I am expecting it to go, then I may revisit the gear design because less drag means more speed.

The assembly begins by securing the ailerons to the wing halves with thin CA. The servos are then either glued to the bay covers or screwed to the supplied blocks that are glued to the covers. I glued my servos to the covers with CA.

I had two Hitec HS-322HD servos and two HS-81 mini servos available so I decided to use the heavier (and larger) 1.5oz HS-322 servos for the aileron control since it was near the CG. The lighter 0.6oz HS-81 servos will be used in the back for elevator control.

All the hardware was supplied in the kit including the nut and keepers for added security. A string was installed inside the wing to help pull the servo wire through to the end.

I skipped over the gear installation to install the wings. The fiberglass fuselage was only cut out for the aluminum bar so you needed to drill two holes for the wooden dowel supports and a slot for the servo control wire on each side. The fuselage had impressions for these areas so it was easy to drill and cut in the proper places. The four wooden dowels, two per wing half, were glued to the wing with epoxy. A T-nut is pre-installed in each wing half between the aluminum bar and servo wire opening. Once the wing is pressed against the fuselage, a M4x20mm hex head screw and washer hold it securely in place from inside the fuselage.

There wasn't a photo for the missile assembly but I could see the correct orientation from the "Main Wing" drawing on the back of the manual. This was a two step process in which you first glued the missile mounting piece onto the wing end, with 5-minute epoxy, and then glued the missile in place. I shaved the side of the missile to be glued flat before gluing it in place. The covering was also removed from the wing end before gluing the mounting piece in place.

I'm a bit backed up with other projects and the AMMO motor I want to use doesn't get released for another month so there may be some delay in my posts. Since this model requires a runway (grass or paved) I can't fly it until Springtime hits upstate NY in April or May anyway.

Read it again...it says two 4s in series for an 8-cell total. This is my best guess. It may actually use 8s to 10s depending upon my measurments. Sometimes the Kv rating on motors is not always accurate so it is important to take measurements of current, power, and RPMs.

A 101mm fan is the maxiumum that will fit. A smaller fan can be used in many applications, especially if it is more efficient and more powerful. Sometimes a smaller fan can be used to reduce weight as well because the motor, ESC, and batteries weigh less.

Greg you may already have looked at the other site that deals with electrics that has zone in it but I thought I would point this out to you in case you havent. Some of the guys have stated that there may be a nice CG error with regard to what the manual states. Might be worth looking into.

Nitro only has a recommendation for a power system for the model without specifics. It is merely a suggestion. I am trying my own new setup using a motor that has not even hit the market yet. If it works, it will provide more power for less cost than others in the same range. Time will tell...

Harry,

Thanks for the heads up. Don't be afraid to say E-Zone or RC Groups here. I started my electric flight obssesion as a moderator on the E-Zone back in the late 90's until about 2003. If you saw the manual for this Predator UCAV EDF, you would be suspicious of the CG too. It is the price we pay for such a discounted yet excellent value model. I will take a closer look at the CG soon.

I thought this next step was going to be much more difficult but it turned out quite easy since the non-marked area to be cut inside the servo frame was soft enough to use just a razor knife.

The Hitec HS-81 servos fit perfectly in the plywood bay frame opening. I secured 36" HD extensions to the control lines by first tying the connectors with Firewire and then covering them with shrink wrap. The lighter .6oz HS-81 servos will provide 42oz/in torque on my 6v CC BEC.

The elevator linkages installed nicely using the included hardware and keepers. One servo was connected to the elevator input on my Spektrum receiver and the other was mixed into the AUX2 channel. When using a Spektrum receiver, remember to use mixes 5 or 6 to have the trim work both channels together.

I know where the CG issues are coming from now. I couldnt pass up this nice looking airplane for 130 bucks so I got one and have it 90% done.

The motor is no where near far enough back. To even get close to hitting the CG with where the motor sits even when its all the way back in the saddle you will have to put weight in the back or slide the batteries over the intakes on the airframe. I had to line up the back edge of my packs with the lip of the inlet and I was at about 7.25 inches back from the wing. That was with my 8S1P 3850 packs. I plan on going with an 8S2P 4000 but this is going to add another few ounces and I dont know how much farther back I can reall y push it before the packs get into the airflow. Not that it will matter a whole bunch as long as I am not restricting the airflow since I am not going to run inlet ducts but then its a pain to plug in the batteries.

I'm approaching the point where I can check the CG so I marked settings of 7.25" and 8.25" on the wing bottom.

The main landing gear mounted very well without any issues. The holes were pre-drilled in the fuselage and T-nuts already mounted in the former. I only needed to cut off the excess axle length with a Dremel tool.

The steerable nose gear installation was not as easy. The hole for the gear wire was not marked on the fuselage so I installed the plastic piece inside the fuselage first since the T-nuts were already installed. I used a long rod with a sharpened end to press through the gear wire holes on the plastic piece to create an aligned hole from the inside to the outside. The hole was then opened with a 11/64" drill bit.

All the holes in the plastic piece also needed to be opened. I used a 1/8" bit for the screw holes and a 11/64" bit for the gear wire. The smaller nose wheel hole was also opened with an 11/64" bit. Once installed, it allowed me to finally sit the Predator UCAV on its own wheels.

Thanks. I was little bummed to see that the release of the new Great Planes ElectriFly Ammo [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXLXA1&P=7]36-88-1280kV[/link] Brushless Electric Motor was delayed until late May. I am hoping to use it in this project as a new choice for the highest power at the lowest cost.